Self assembled temperature responsive surfaces for generation of cell patches for bone tissue engineering

Tissue engineering relies on scaffolds that can support cell growth and tissue formation. Current methods for seeding cells onto scaffolds face limitations in efficiency, uniformity, and depth of cell penetration. Scaffold design innovations, such as increased porosity and surface area, often complicate cell seeding further. While cell sheet-based techniques offer promising alternatives, the preparation of temperature-responsive surfaces remains a challenge due to the use of toxic chemicals and irradiation. This gap motivated researchers to explore safer and more efficient methods for generating cell patches for tissue engineering applications.

This study aimed to develop a safer and more effective method for generating temperature-responsive surfaces suitable for cell patch formation. The goal was to avoid carcinogenic reagents and gamma irradiation typically used in such methods. The researchers focused on creating surfaces that allow for uniform cell attachment and easy detachment by changing temperature. The approach also aimed to improve cell seeding efficiency and promote better tissue formation when cells are transferred onto porous scaffolds.

The researchers used a layer-by-layer self-assembly technique to fabricate thin films. The films were composed of tannic acid and poly N-isopropylacrylamide, selected for their electrostatic and hydrogen bonding properties. The surface was tested for cell attachment and proliferation. Cells were cultured on the thin films and then harvested as cell patches by lowering the temperature. These patches were then transferred onto porous scaffolds to evaluate their seeding efficiency and tissue-forming potential.

The temperature-responsive thin films supported uniform cell attachment comparable to standard tissue culture plates. Cells could be easily harvested as patches by reducing the temperature for a short time. When transferred to porous scaffolds, the cell patches demonstrated higher seeding efficiency than cells seeded in suspension. The pre-formed cell-cell and cell-extracellular matrix interactions in the patches enhanced their ability to reattach and proliferate on scaffolds. The patches also showed improved differentiation into a bone-like matrix. These findings suggest that the cell patch-based method is more effective for tissue engineering applications.

The study demonstrated that temperature-responsive surfaces fabricated using tannic acid and poly N-isopropylacrylamide can support uniform cell attachment and efficient cell patch formation. The patches showed improved seeding efficiency and tissue formation when transferred to porous scaffolds. The method avoids the use of carcinogenic reagents and gamma irradiation, offering a safer alternative for cell patch generation. The cell patches retained cell-cell and cell-extracellular matrix interactions, which enhanced their ability to reattach and differentiate into bone-like tissue. These findings suggest that the developed method could be useful for tissue engineering applications.